1. Project summary: The broad, long-term objective is to develop a Scanning ocular Aberration Measurement (SAM) system that solves five shortcomings of current wavefront sensors. Most or all current systems: 1) are too expensive for deep market penetration, 2) do not monitor the pupil size and location as a function of illumination and accommodation, 3) are not designed to change the accommodative demand dynamically as exams are acquired, 4) do not allow spatial sampling density to be adjusted as required depending upon the severity of the aberration structure being measured, and 5) fit the wavefront aberration with a Zernike polynomial without evaluating the impact of the resulting smoothing error and do not provide an alternative fitting method. To achieve the goal of meeting these 5 shortcomings, the specific aims for Phase II will be to: develop the SAM hardware, develop the SAM system software, develop the SAM system calibration and test items, and integrate these SAM components and perform a system level test. The commercial applications for the SAM system include clinical measurements to support custom vision correction interventions such as cornea laser surgery, custom contact lens, and custom implantable lenses. The instrument will also be able to provide an extended range of measurements for clinically difficult cases such as keratoconus or cornea transplants. Health relatedness is achieved in that a cost effective instrument with improved utility capable of handling a broader range of patients quickens the transfer of proven laboratory technology to clinical care. Technological innovations include a variable spatial sampling dependent on need by scanning a micro-lenslet array and its micro-aperture array, a see-through design, and pupil location monitoring as a function of ambient illumination and accommodation. [unreadable] 2. Relevance: The SAM system will provide a cost effective instrument capable of measuring a broader range of patient's ocular aberrations than is currently available. In addition, the ability to measure these aberrations dynamically while the eye is changing focus from a distant to a near object will be provided. [unreadable] [unreadable] [unreadable] [unreadable]